asn.dev

Observed topology

AS237 MERIT-AS-14

Unclassified ARIN

Upstreams 9 carry this network
Downstreams 34 this network carries
Adjacent (IPv4) 42
Adjacent (IPv6) 14
Upstream graph Who carries AS237, and who carries them, drawn as a map up to the transit-free core. 2 exchanges Where AS237 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS237: the AS immediately before it in a routing path. Ranked by how many paths showed the relationship, which reflects how widely it is used, not how much traffic crosses it.

ASNetworkTypeFamiliesPaths seen
AS1299Arelion Sweden ABTransitIPv4 IPv61,864
AS2914NTT America, Inc.TransitIPv4 IPv6870
AS174Cogent Communications, LLCTransitIPv4 IPv6820
AS6939Hurricane Electric LLCTransitIPv4 IPv6810
AS11537Internet2UnclassifiedIPv4 IPv6417
AS7018AT&T Enterprises, LLCResidentialIPv4 IPv6218
AS11164Internet2EducationIPv4 IPv6184
AS293ESnetUnclassifiedIPv483
AS3303Swisscom (Schweiz) AGResidentialIPv481

Transit

Downstream networks

All 34

Networks for which AS237 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS11206Ferris State UniversityEducationIPv41,951
AS25609Detroit Medical CenterUnclassifiedIPv4979
AS36375University of MichiganUnclassifiedIPv4 IPv6965
AS231Michigan State UniversityUnclassifiedIPv4 IPv6400
AS400238PIE&GUnclassifiedIPv4225
AS27274Central Michigan UniversityUnclassifiedIPv4 IPv6219
AS62618Michigan Technological UniversityEducationIPv4185
AS22251Regional Educational Media Center 1 (REMC1)UnclassifiedIPv4125
AS62676University of Michigan - DearbornUnclassifiedIPv4124
AS1638Mott Community CollegeEducationIPv4122

All 34 downstreams →

Adjacency

Adjacent networks

All 43

Every AS seen directly next to AS237 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS1299Arelion Sweden ABTransitIPv4 IPv64,258
AS11206Ferris State UniversityEducationIPv41,951
AS174Cogent Communications, LLCTransitIPv4 IPv61,930
AS6939Hurricane Electric LLCTransitIPv4 IPv61,686
AS2914NTT America, Inc.TransitIPv4 IPv61,604
AS11537Internet2UnclassifiedIPv4 IPv61,153
AS25609Detroit Medical CenterUnclassifiedIPv4979
AS36375University of MichiganUnclassifiedIPv4 IPv6965
AS7018AT&T Enterprises, LLCResidentialIPv4 IPv6522
AS231Michigan State UniversityUnclassifiedIPv4 IPv6461

All 43 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-21 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.14M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.

Inferred from path position, not from any declaration by either party. A network appearing here is carrying these routes; whether that is a paid transit arrangement, a backup, or something else is not something routing data can tell you. Adjacency is not the same as peering. Being next to each other in a path covers paid transit, settlement-free peering and customer connections alike, and routing data cannot distinguish them. Treat this as "these networks exchange routes", nothing more specific.

Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.